Flush valve

ABSTRACT

Described here are flush valves for delivering a selected amount of water from a toilet tank into a toilet bowl, particularly collapsible flush valves having substantial durability and resistance to wear and deleterious chemicals. These flush valves have a collapsible member extending from above the surface of the water in the toilet tank to the tank outlet in the normal (closed flush valve) state. Collapsing the flush valve allows water to flow into the toilet bowl through the flush valve until the toilet tank is drained to the level of the collapsed flush valve and buoyancy is restored. Flush valves may be made of a material that does not substantially deteriorate in the presence of halogen-containing toilet disinfectants, and the outer surface (the water contacting surface) of the flush valves may be a single continuous piece.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.10/875,363, filed on Jun. 23, 2004, the disclosure of which is herebyincorporated by reference in its entirety.

FIELD

Described here are flush valves for delivering a selected amount ofwater from a toilet tank into a toilet bowl, particularly collapsibleflush valves having substantial durability and resistance to wear anddeleterious chemicals. Also described are methods of making and usingthe described valves. These flush valves typically include a collapsiblemember extending from above the surface of the water in the toilet tankto the tank outlet in the normal (closed flush valve) state. The flushvalve is relaxed in the extended (closed) position. Collapsing the flushvalve allows water to flow into the toilet bowl through the flush valveuntil the toilet tank is drained to the level of the collapsed flushvalve and buoyancy is restored. The valves may be made of a materialthat does not substantially deteriorate in the presence ofhalogen-containing toilet disinfectants. At least the outer surface (thewater contacting surface) of the flush valves may be a single continuouspiece.

BACKGROUND

Most residential toilets use a flapper valve to regulate the passage ofwater from the toilet tank to the toilet bowl. A toilet is typicallyflushed by depressing the flush handle to lift the flapper valve,thereby allowing water in the toilet tank to exit into the bowl. Watercontinues to flow from the toilet tank into the bowl until the flappervalve pivots back down to once more seal the tank, allowing the toilettank to refill.

Water conservation is increasingly important to water districts and toindividuals faced with finite (or often dwindling) supplies, greatercosts, and often growing demand for water resources. Toilets are thelargest single water user in most homes, and flapper valves are thenumber one source of household water leakage. The flapper valve is proneto leakage because it is a moving seal that must be unsealed andresealed with every flush. According to a study conducted by the USDepartment of Housing and Urban development, 20% of household toiletsleak, including 12% of low-flush toilets, primarily due to failure ofthe flapper valve.

A number of factors can contribute to leakage or failure of flappervalves. For example, debris can become lodged between the flapper andits seating seal (valve seat). Moreover, the flapper valve is ordinarilysubmerged in the toilet tank, and water and/or toilet bowl cleansers maycorrode, rot or swell the flapper valve. Halogenated toilet bowlcleaners are particularly destructive to flapper valves. Further,flappers can warp or deform due to swelling or age. Algae can also growon the flapper valve parts, adversely affecting performance. Finally,flapper valves may become misaligned with continuous use. Ironically,flapper valve leakage often increases after replacement of an existingflapper valve, perhaps because the new flapper valve is mismatched tothe existing valve seat. There are currently no “standard” flapper valvegeometries and it is difficult to know which valves to use to replaceexisting valves.

It is desirable to provide a flush valve which is less likely to leak,and which may be readily adapted to existing toilet tank designs.Currently, there are no commercially available flush valves thatsignificantly resist leaking and are resistant to corrosion by thestrongest available toilet bowl cleansers.

Two similar types of flush valves have been suggested to replace flappervalves: collapsible tubes, and siphon-type flush valves.

U.S. Pat. Nos. 6,381,764 and 6,199,221 to Stalhut show a toilet tankflush valve with a collapsible tube attached by O-rings to the tankoutlet and also to a float which is capable of switching between highand low buoyancy. The valve is operated by depressing an actuating rodheld in the middle of the collapsible tube. Similar collapsible tubevalves are shown in U.S. Pat. No. 6,397,404 to Ferreyra et al., USpatent application number 2003/0233703 to Parker, U.S. Pat. Nos.3,183,526 and 3,280,407 to Aaron, U.S. Pat. No. 815,661 to Vissing, andU.S. Pat. No. 692,611 to Burgum.

U.S. Pat. No. 6,473,912 to Preciado-Villanueva shows a siphon flushvalve in which a sliding conduit is attached (by a fixing means such asadhesives or mechanical means, column 3, line 65) to a fixed conduit andattached to a flow-directing element. The valve is operated by pushingdown on the flow-directing element so that water begins to siphon intothe sliding conduit. Similar collapsible tube valves are shown in U.S.Pat. No. 386,918 to Demarest.

None of the cited prior art suggests the device and methods describedand claimed below.

SUMMARY

Described here are flush valves and methods for installing, using andmaking them. In particular, this application describes collapsible flushvalves having substantial durability and resistance to wear anddeleterious chemicals. The flush valves described herein may be used tocontrollably deliver a selected amount of water from a toilet tank intoa toilet bowl without using a valve seat, because the flush valveoperates by buoyantly holding the opening into the tank outlet portabove the surface of the water in the toilet tank until the toilet isflushed.

In one version a flush valve for controllably delivering a selectedamount of water to a toilet bowl from a toilet tank comprises acollapsible member configured to extend from the water surface of waterin the toilet tank down to the tank outlet in a first or extendedposition. This extended position is maintained when the flush valve is“closed,” preventing the flow of water from the resting toilet tank intothe toilet bowl. The flush valve maintains the level of water in thetoilet tank by not allowing it to flow into the toilet bowl. The flushvalve may release water from the toilet tank through the tank outlet byassuming a second position in which the collapsible member of the flushvalve is longitudinally collapsed. The flush valve may be in the“relaxed” position (meaning there are minimal, if any, spring forcesacting on the collapsible region of the flush valve collapsible member)when the flush valve is extended in the toilet tank (the extendedposition). Since the flush valve spends most of its useful lifetime inthe closed position, preventing toilet tank water from passing into thetoilet bowl, reducing spring forces on the flush valve may substantiallyextend the lifetime of the flush valve. Further, the flush valvecollapsible member may comprise one or more materials that do notsubstantially deteriorate in the presence of halogen-containing toiletdisinfectant solutions; for example, rubbers, polymers, or combinationsthereof which do not break down or loose their material properties whenexposed to halogen-containing toilet disinfectants in a toilet tank forextended amounts of time (e.g. weeks, months or years). Further, theflush valve does not have a valve seat, as would be found inflapper-type flush valves and other comparable flush valves.

In some versions, the flush valve collapsible member is fabricated as asingle, continuous piece. In some versions, all of the outer surfaces ofthe flush valve that are exposed to toilet tank water when the tank isfull, and the valve is closed, are made as a single piece. Thus, thereare no (potentially leaky) connections between separate components ofthe flush valve.

In some versions, the flush valve may also include at least one ballastweight. Ballast weights may help overcome the forces preventing theflush valve from collapsing to “open” and allow passage of water fromthe toilet tank into the toilet bowl (e.g. spring forces, materialbuoyancy, etc). In some version, ballast weight may help apply force tocollapse the flush valve. Because the neutral position of the flushvalve is in the extended (flush valve closed) position, collapsing theflush valve may be facilitated by ballast weights. The weights may beattached anywhere on the flush valve, especially the upper region(closer to the surface of the water in the toilet tank), for example, onthe bottom of the buoyant region of the flush valve.

In some versions, the flush valve collapsible member comprises a baseregion, a float region, and a collapsible member that are fabricated asa continuous single piece. Sinking the float region allows thecollapsible member to collapse and allows water to flow through thecollapsible member and out of the tank outlet (“opening” the flushvalve). The collapsible region of the collapsible member may be acollapsible bellows.

In some versions, the flush valve is opened by pushing on a tippingactuator. Thus, the flush valve may include a tipping actuator forsinking the float region of the flush valve.

In some versions, the base region, float region, and collapsible memberof the flush valve are fabricated as a single piece by molding. In someversions, this molding is injection molding. In other versions, thismolding is blow molding.

In some versions, the collapsible member may have a continuous spiralthread. For example, the “bellows” ridges of a collapsible member mayactually be one or more continuous ridges spiraling around the outeredge of the collapsible region from the top (near the water surface) tothe bottom (near the tank outlet port). The entire flush valve may betapered (e.g. may be wider at the top than the bottom), or just thecollapsible member may be tapered. Tapering may assist in fabricatingthe flush valve as a single continuous piece. Similarly, the flush valvemay be radially symmetrical, which may also facilitate fabrication as asingle piece.

The flush valve may be fabricated from a polymer such as a polyolefin.In particular, the flush valve may be fabricated from a Very Low DensityPolyethylene (VLDPE, for example, FLEXOMER DFDA-1095 NT from DOWChemical Company, or EXACT™ 5371 from ExxonMobile Chemical), Ultra LowDensity Polyethylene (ULDPE, for example, ATTANE® 4404 G from DOWChemical Company), or soft vinyls (such as Tygon®).

In some versions, the flush valve further comprises a longitudinal shaftcoupled to the collapsible member (for example, at the base region)wherein the shaft is configured to substantially guide the flush valvewhen the collapsible member collapses. The shaft may also include“stops” preventing the upper opening into the flush valve fromcollapsing beyond a set position. The shaft may be centrally positionedin the lumen of the flush valve (e.g. positioned near the long axis ofthe flush valve) or may be positioned off of the center (includingexternal to the lumen of the flush valve).

Also described herein are flush valves for controllably delivering aselected amount of water to a toilet bowl from a toilet tank, the toilettank having a water surface and a tank outlet, comprising a collapsiblemember configured to extend from the water surface to the tank outlet ina first extended position and to maintain the water in the toilet tank.The collapsible member is further configured to release water from thetoilet tank through the tank outlet when it collapses longitudinally andtakes a second, collapsed, position. The flush valve collapsible membercomprises one or more materials that do not substantially deteriorate inthe presence of halogen-containing toilet disinfectant solutions. Theseflush valves also do not have a valve seat. In one version, thecollapsible member is fabricated as a single continuous piece.

In one version of the flush valve, the collapsible member is configuredto be substantially relaxed in the extended position. In some of theseversions, the flush valve further comprises a ballast weight. The flushvalve collapsible member may comprise a base region, a float region, anda collapsible member; sinking the float region allows the collapsiblemember to collapse and allows water to flow through the collapsiblemember and out of the tank outlet.

In some version of the flush valve, the flush valve further comprises atipping actuator for sinking the float region of the flush valve. Insome versions of the flush valve, the base region, float region, andcollapsible member are fabricated as a single piece by molding, forexample, injection molding or blow molding.

In some versions, the collapsible region of the flush valve is acollapsible bellows; in some versions this collapsible bellows has acontinuous spiral thread (or ridge) at the bellows fold, extending fromthe top of the flush valve to the bottom. In some of these versions, thecollapsible bellows is tapered.

The flush valve may be fabricated from a rubber, a polymer, or acombination thereof. In one version, the flush valve is fabricated froma polyolefin, in particular a Very Low Density Polyethylene (VLDPE, forexample, FLEXOMER DFDA-1095 NT from DOW Chemical Company or EXACT™ 5371from ExxonMobile Chemical), Ultra Low Density Polyethylene (ULDPE, forexample, ATTANE® 4404 G from DOW Chemical Company), or soft vinyls (suchas Tygon®).

In some versions, the flush valve further comprises a longitudinal shaftcoupled to the collapsible member wherein the shaft is configured tosubstantially guide the flush valve when the collapsible membercollapses.

Also described herein are flush valves for controllably delivering aselected amount of water to a toilet bowl from a toilet tank, the toilettank having a water surface and a tank outlet, comprising a collapsiblemember configured to extend from the water surface to the tank outlet ina first extended position and to maintain the water in the toilet tank.The flush valve is further configured to release water from the toilettank through the tank outlet in a second, longitudinally collapsed,position. The flush valve further comprises a ballast weight sufficientto collapse the collapsible member.

In some versions, the flush valve also comprises one or more materialsthat do not substantially deteriorate in the presence ofhalogen-containing toilet disinfectant solutions. In some versions, thecollapsible member is fabricated as a single continuous piece isconfigured to be substantially relaxed in the extended position.

Also described herein are flush valves for delivering water to a toiletbowl from a toilet tank comprising a base region configured to connectto the outlet port of a toilet tank, a floatable and sinkable floatregion having an opening that is held above the surface of the waterwhen the float region is floating, and wherein the float region islinked to the base region through a collapsible member extending fromthe base region to the float region. The base region, float region andcollapsible member are fabricated as a single piece. Sinking the floatregion allows water to flow through the opening of the float region andout of the outlet port of the toilet tank. In some versions, the flushvalve further comprises a ballast weight. In some versions, the flushvalve further comprises a tipping actuator for sinking the float regionof the flush valve. In some versions, the collapsible member is relaxedin the extended position.

In some versions, the flush valve may also include a flow cone attachedto upper region of the flush valve (e.g. the float region) configured tomodify the passage of water into the opening of the float region.

Also described herein are flush valves for delivering water to a toiletbowl from a toilet tank comprising a molding-formed collapsible memberconfigured to extend from the water surface to the tank outlet in afirst extended position and to maintain the water in the toilet tank inthis extended position. The flush valve is further configured to releasewater from the toilet tank through the tank outlet when the collapsiblemember of the flush valve collapses into a second longitudinallycollapsed position. This version of the flush valve has a collapsiblemember that is spirally threaded. Further, the flush valve has no valveseat. In some versions this flush valve is tapered.

In some versions, the flush valve further comprises a ballast weight. Insome versions, the flush valve further comprises a tipping actuator forsinking the float region of the flush valve. In some versions, thecollapsible member is relaxed in the extended position.

Also described herein are methods of using the described flush valvevariations. In general, the flush valves described herein may be used toprovide water from a toilet tank into a toilet bowl by at leastpartially sinking the flush valve. In some versions, the flush valve ispartially sunk by applying force (e.g. by pushing) on a tippingactuator. In some versions, the tipping actuator applies force to theupper portion of the flush valve (e.g. a float region) to collapse thecollapsible member of the flush valve.

Also described herein are methods of using a flush valve comprising atleast partially sinking a float region of a flush valve in a toilet tankhaving an outlet port in fluid connection with a toilet bowl. The flushvalve comprises a base region configured to connect to an outlet port ofthe toilet tank, a variably buoyant float region configured to switchbetween a high buoyant state and a low buoyant state, and having anopening that is held above the surface of the water when the floatregion is highly buoyant, wherein the float region is linked to the baseregion through a collapsible member extending from the base region tothe float region. The float region and the collapsible member arefabricated as a single piece from one or more materials that do notsubstantially deteriorate in the presence of halogen-containing toiletdisinfectant solutions.

Also described herein are methods of using a flush valve in a toilettank containing water comprising at least partially sinking a flushvalve. The flush valve comprises a collapsible member configured toextend from the water surface to the tank outlet in a first or extendedposition and to maintain the water in the toilet tank, and thecollapsible member is further configured to release water from thetoilet tank through the tank outlet in a second, or longitudinallycollapsed, position. The collapsible member comprises one or morematerials that do not substantially deteriorate in the presence ofhalogen-containing toilet disinfectant solutions, is fabricated as asingle continuous piece. The collapsible member is configured to besubstantially relaxed in the extended position.

Also described herein are methods of installing a flush valve in atoilet tank, where the toilet tank has an outlet port in fluidconnection with a toilet bowl. The method of installing the flush valvecomprises providing a flush valve and installing the flush valve ontothe outlet port of the toilet tank. The flush valve comprises a baseregion configured to connect to the outlet port of a toilet tank, avariably buoyant float region configured to switch between a highbuoyant state and a low buoyant state, and has an opening that is heldabove the surface of the water when the float region is highly buoyant.The float region of the flush valve is linked to the base region througha collapsible member extending from the base region to the float region.The float region and the collapsible member are fabricated as a singlepiece. In some versions, the flush vale is installed by tightening anut.

Also described herein are methods of fabricating a flush valvecomprising injection molding a flush valve. The flush valve to beinjection molded comprises a base region configured to connect to theoutlet port of a toilet tank, a variably buoyant float region configuredto switch between a high buoyant state and a low buoyant state, havingan opening that is held above the surface of the water when the floatregion is highly buoyant, wherein the float region is linked to the baseregion through a collapsible member extending from the base region tothe float region. The float region, base region and the collapsiblemember of the flush valve are injection molded as a single piece. Insome versions, the flush valve is injection molded from one or morematerials that do not substantially deteriorate in the presence ofhalogen-containing toilet disinfectant solutions. In some versions, theflush valve is tapered.

Also described herein are methods of fabricating a flush valvecomprising injection molding a collapsible member configured to extendfrom the upper water surface of a substantially filled toilet tank tothe tank outlet in a first extended position to maintain the water inthe toilet tank, and further configured to release water from the toilettank through the tank outlet in a second, longitudinally collapsed,position, wherein the collapsible member is further configured to besubstantially relaxed in the extended position. The collapsible memberis injection molded from one or more materials that do not substantiallydeteriorate in the presence of halogen-containing toilet disinfectantsolutions.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments or variations are now described by way of example withreference to the accompanying drawings.

FIG. 1 shows a schematic illustration of an integrated flush valve;

FIG. 2 shows the flush valve of FIG. 1 in the collapsed position;

FIG. 3A to 3C show top views of the insides of the upper float chamber;

FIG. 4 shows a schematic illustration of another version of anintegrated flush valve;

FIG. 5A shows an integrated flush valve having a tapered bellows;

FIG. 5B shows an integrated flush valve;

FIG. 6 shows an integrated flush valve installed in a toilet tank;

FIG. 7A to 7C illustrate the activation of an integrated flush valve.

DETAILED DESCRIPTION

Described here are integrated flush valves for use in toilet tanks,methods of manufacturing the flush valves, and methods of using theflush valves. In the drawings, reference numeral 10 generally denotes anexemplary embodiment of an integrated flush valve. For the sake ofbrevity, an integrated flush valve will be referred to as a “flushvalve.”

FIG. 1 shows a flush valve 10 in an extended position. The flush valveis a collapsible member which comprises a hollow integrated unit havingregions corresponding to an attachment base region 101 which attaches tothe output port of a toilet tank (tank outlet), a collapsible tube (orbellows or member) region 103 that prevents the passage of water whenextended and allows the passage of water when the tube is collapsed, anda float region 105 which may provide an upward buoyancy when the flushvalve is in the resting state. These regions of the flush valve arepreferably sub-regions of a single integrated component.

Because the flush valve in FIG. 1 is integrated, all of the flush valvesurfaces which contact fluid (e.g. water) in the inactive state (whenthe valve is “shut”) are continuous. Thus, there is no need for seals orconnections between the different regions of the flush valve. This hasmany advantages over flush valves which comprise separately joinedregions, including cost and durability. The fewer seals that a flushvalve has, the less chance it will leak. Further, flush valves withfewer components are generally less expensive to produce than valvesrequiring the assembly of multiple components.

The flush valve shown in FIG. 1 is formed as a single piece, and thusdoes not have any joints or seals which may degrade and potentiallyleak. The outer diameter of the flush valve provides sufficientclearance to allow lateral (“up/down”) movement within the tank. Asillustrated in FIG. 6, the outer surface of the flush valve (shown inFIG. 1) is exposed to water in the toilet tank, and acts as a barrier,preventing water in the toilet tank from flowing into the tank outletport until the flush valve is activated. The inner region of the flushvalve 109 is hollow, and forms a continuous fluid connection with theoutlet port of the toilet tank.

FIG. 2 shows the flush valve of FIG. 1 in the longitudinally collapsedposition. The collapsible member of the flush valve 10 collapses toreduce the height of the flush valve. The change in height may depend onthe structure of the collapsible member. When the collapsible tube is abellows (as shown), the collapsible tube height changes by folding,accordion-style. The collapsible tube 103 collapses when the floatregion loses buoyancy, for example, when the float region is tilted andtakes on water. Losing buoyancy means that the upper, float region ofthe flush valve will sink, allowing water to flow through the centralchannel of the flush valve and out of the tank through the outlet port.

The inner region of the flush valve 109, may modify the activity of theflush valve. In one version, the flush valve includes inward radiatingstruts 301 to support a rod or shaft. The inner region may also includeadditional attachment sites. In one version, the inner diameter of atleast a region of the flush valve (e.g. the collapsible member) isoptimized to increase the fluid flow exit rate.

Attachment Base Region

The attachment base region 101 may attach into the tank in the same wayas would any standard flush valve attachment. In one version, theattachment region attaches by a fixed elastomeric seal compressed with alarge plastic nut. Thus, the outer wall or the inner wall of theattachment base region may be threaded or otherwise textured tofacilitate attachment to the outlet port of the toilet tank.

The inner diameter of the attachment base region may be adapted tomodify the flow of liquid from the toilet tank, or it may includesupports or struts. Supports or struts may be useful to provide enhancedstrength for the attachment base region. Further, supports or struts maybe used to support a rod or shaft in the flush valve. In one version,the inner diameter of the attachment base region is narrower than otherregions of the flush valve. In one version, this narrowing of the innerdiameter of the attachment base region enhances the flow rate orpressure entering into the toilet bowl.

The inner surface of the attachment base region may be an integral partof the flush valve, or it may have additional materials attached to it.The outer surface of the attachment base region, as with the outersurface of the entire flush valve, is preferably made as one singlecontinuous piece.

In one version of the flush valve, the base region of the flush valvecomprises a sleeve which attaches to an attachment adapter for sealingthe base of the toilet tank to the tank outlet port. An attachmentadapter may include, for example, a threaded nut adapter. In oneversion, one end of the threaded nut adapter is attached to the baseregion of the flush valve. The threaded nut adapter passes through thetank outlet port, and the nut is screwed onto the threaded adapter onthe opposite side. A water tight seal is formed when the nut istightened, forcing the base region of the flush valve against the bottomand/or sides of the outlet port. This type of attachment adapter worksparticularly well when the base region is made of a compressibleelastomeric material.

Flush valves as described above may be used with existing (“standard”)toilet tanks. Thus, the outer diameter, thickness, height and otherdimensions of the attachment base region may be adapted to fit thedimensions of any existing toilet tank, particularly the outlet portsfor the commercially available toilet tanks. Of course, the dimensionsof the attachment base region may be adjusted to fit virtually anytoilet tank output port.

In one version, the outer diameter, thickness and height of theattachment base region are adapted to attach to a toilet tank having anoutlet port 2 inches in diameter. In one version, the outer diameterthickness and height of the attachment base region are adapted to attachtot a toilet tank having an outlet port 3 inches in diameter. The actualdiameter of the outlet port may be determined based on industry orgovernment standards.

Collapsible Member

The collapsible member (collapsible tube region) 103 allows the flushvalve to change height by elongating or compressing (collapsing) whenthe float region gains or loses buoyancy. In one version, thecollapsible tube is a bellows.

Preferably, the collapsible member is capable of undergoing manythousands of compression/expansion cycles over a lifetime of many years.The collapsible region collapses (contracts) each time the flush valveis activated to allow fluid to flow out of the flush valve. At the endof the flush cycle, the collapsible member expands to prevent fluid fromflowing out of the flush valve.

The structure of the collapsible member may be optimized for durability,strength, and function. In one version, the wall thickness of thecollapsible member is substantially uniform. In one version, the wallthickness is adjusted to accommodate the repeated motions of thecollapsible member; for example, by reinforcing the parts of thecollapsible member requiring greater material strength.

The collapsible member of the flush valve shown in FIGS. 1 and 2 arebellows having one or more continuous ridges that coil around thecollapsible member. This results in a threaded appearance. Thedimensions of the “threads” in the collapsible tube may, in part,determine how compressible the collapsible region is (e.g. how far theflush valve collapses or changes its height). The threaded collapsiblemember is particularly advantageous in fabricating the integrated flushvalve, as described below. A collapsible tube region (or a region of acollapsible member of a flush valve) having one or more continuousthreads has one or more ridges (threads) that begin at the top of thecollapsible region and continue to the bottom of the collapsible region.Thus, the continuous thread(s) run, screw-like, around the collapsibleregion. A continuous thread may be substantially continuous, meaningthat the thread may be interrupted (for example, by some otherstructure) but then continue as if it had not been interrupted.

In one version, the collapsible tube has two or more threads forming thebellows. The threads are intertwined around the perimeter of thecollapsible tube and their starting points (e.g. at the top or bottom ofthe collapsible member) may be equally spaced from each other. Balancingthe threads this way may prevent unequal compression and torsion of thecollapsible tube.

The dimensions of the collapsible member may vary depending upon thedesign specifications. Thus, a fully extended collapsible member shouldallow the upper surface of the flush valve to extend beyond the maximumdesirable tank fill level. The collapsed form of the flush valve shouldplace the opening of the collapsible member of the flush valve atapproximately the high of the completed tank flush level. Thus, if a sixliter flush is to be delivered, the collapsible member should collapseat least to a height which will deliver six liters of fluid. A selectedamount of water can be controllably delivered by the flush valve; forexample by selecting the height to which the flush valve collapses.

In some versions, the collapsible member will have a spring moduluswhich may effect the operation of the flush valve. Thus, if thecollapsible member is a bellows, the dimensions and the material chosenfor the flush valve may, in part, determine the spring modulus of theflush valve. In some cases, the spring modulus describes the forcerequired to move the collapsible member either in expansion orcompression. In one version, the spring modulus is adjusted, forexample, by the material used to form the flush valve, or by treatingthe flush valve (e.g. by heat) to pre-set the resting state of thecollapsible tube.

In one version, the collapsible tube is substantially extended in theneutral (relaxed) position. Thus, the collapsible tube, and thereforethe flush valve, relaxed in the extended position in the filled toilettank. In this extended state there are minimal (or perhaps no) springforces acting on the collapsible tube. This “low stress neutralposition” (or zero-stress neutral position) may enhance the durabilityand lifetime of the flush valve, as described further below. The “lowstress neutral position” is that position where movement of thecollapsible member along its axis, i.e., expanding or contracting, willexhibit a positive or negative spring force. When the flush valve issubstantially extended, the collapsible region of the collapsible member(flush valve) is extended longitudinally along the long axis of theflush valve; in a water filled toilet tank the substantially extendedposition is one in which the top portion of the collapsible member isabove the surface of the water.

In one version, the collapsible member of the flush valve is tapered sothat the inner diameter of the flush valve is greater in the upper partof the collapsible member than it is in the lower part of thecollapsible member. For example, see FIG. 5A. Thus, the collapsiblemember appears tapered. In one version, the collapsible member istapered and threaded.

Alternatively, the collapsible member may be a pliable region. In oneversion, the collapsible member comprises a pliable sheet formed into acollapsible member. In this version, the collapsible member may belaterally supported by adding an additional internal support, such as aspring or other framework. Thus, although the collapsible member issufficiently pliable to collapse when the float region loses buoyancyand sinks, the collapsible member is also sufficiently laterallysupported to prevent the fluid pressure from constricting thecollapsible member when the float region is buoyant. The outer(fluid-contacting region) of the flush valve is a single continuoussurface, preventing leakage and the need for sealing the differentregions of the flush valve.

Although the collapsible tube is shown as substantially cylindrical, thecollapsible tube may be any cross-sectional shape, including but notlimited to, circular, elliptical, or polygonal (e.g., triangular,square, etc).

Float Region

The float region of the collapsible tube provides upward buoyancy to theflush valve. In the inactive state (when no fluid flows into the flushtoilet bowl through the flush valve), the float region holds the openingof the flush valve above the surface level of the water in the tank. Inone version, the float region is a captured open volume defined by alower surface 131 and a side rim 133, as shown in FIGS. 1 and 2. The toprim 133 remains above the surface of the waterline when the flush valveis inactive so that no water leaves the flush valve from the toilet tankunintentionally. In the neutral position, the buoyant force of the floatregion overcomes the downward force of gravity (weight of the flushvalve) and any spring forces from the collapsible tube. In one version,the collapsible tube has minimal spring forces in the neutral position.

The dimensions of the outer parts of the float region (e.g. the rim 133and the lower surface 131) may vary, for example, depending upon thematerials chosen and the size of the tank in which the flush valve is tobe used. In one version, the rim 133 height is chosen to be relativelylow so that the float region may be readily tipped, making the flushvalve sensitive to user activation. In one version, the lower surface islarger to increase buoyancy. In one version, the thickness of the rimand lower surface are selected to enhance buoyancy while providingadequate structural support.

FIG. 3A to 3C show a top view of features of the inner portion of thefloat region 105. In FIG. 3A, the center portion of the float regioninterior contains an opening into the inner chamber of the collapsiblemember 301, which is in fluid connection with the tank outlet portthrough the attachment base region. In one version, the opening 301 issurrounded by a rim 315. When the flush valve is activated by tippingthe float region, water will enter the inner portion of the float regionand reduce the buoyancy, causing the float region to sink. A raised rim315 slows water from draining out of the float region into thecollapsible member, which may help sink the float region. The height ofthe rim may vary. A taller inner rim means more water will be capturedby the float region after the valve is opened. The more water captured,the greater the weight due to water to “sink” the float region. The rim315 may have one or more small openings to allow water to eventuallydrain from the inner portion of the float region. These openings helprestore buoyancy at the end of the flush valve open cycle, by allowingwater to drain from the float region.

FIG. 3B shows a version of the float region in which the entrance to thecollapsible member is partly occluded by support 320. The support 320both modifies the flow through the flush valve and may help support ashaft or rod. A rod or shaft may pass through an opening 330 in thesupport 320. The dashed lines 303 indicate the location of the outerdiameter of the collapsible member beneath the lower surface of thefloat region. In one version of the float region, the entrance to thecollapsible member contains struts.

In one version of the float region shown in FIG. 3B, a rim 322 surroundsthe entrance into the collapsible member. The rim 322 in FIG. 3B narrowsthe opening (modifying the flow into the collapsible member and out ofthe tank). The rim 322 is also raised above the lower surface of thefloat region. The lower surface of the float region may have holes 325in the lower surface that empty into the collapsible member to allowslow drainage of water from the float region, for example, whenrestoring buoyancy. Alternatively, or in addition, the rim may havedrainage holes.

FIG. 3C shows a version of the float region in which a flow cone hasbeen added to modify the flow of water from the inner portion of thefloat region into the collapsible member and out of the flush valve.Beneath the flow cone (not shown) are holes in the lower surface thatallow the float region to empty (as in FIG. 3B 325). The flow cone maybe of different heights and widths. In one version, the flow cone has acurved surface to guide the water flowing into the flush valve andthrough the tank outlet port. The flow cone may be any height. In oneversion, the flow cone is low, so that the top of the flow cone is nearthe lower surface of the float region. In one version the flow cone istall, so that the top of the flow cone is at least halfway up the wallheight of the float region.

The overall shape of the float region 105 shown in FIGS. 1 to 3 isrectangular, however virtually any shape may be used. In particular, asymmetric shape (e.g. round) may be desirable. FIG. 4 shows an exampleof a circular float region 401. In one version, the float region isshaped to prevent contact with other parts of the toilet tank, such asthe refill inlet, the walls of the tank, and the refill float.

The float region may also include adaptations for contact with a tippingactuator. For example, the flush valve may be actuated by tipping thefloat region so that it becomes at least partly submerged. The floatregion of the flush valve may be tipped by applying force to one or moreparts of the float region. In one version, a tipping actuator appliesforce against the upper surface of part of the float region. In oneversion, float region includes a contact (or “landing pad”)specialization for contacting the tipping actuator. In one version, theupper edge of the float region is flanged to provide a more reliablecontact region for the tipping actuator. In one version, the tippingactuator is attached to the float region.

In one version, the tipping actuator fits into a slot located on theside or top portion of the float region. The slot may be open at the topor may be closed, encircling the tipping actuator. The slot may helpguide the tipping actuator into position with the float region of theflush valve. In one version, the tipping actuator remains within theslot during the entire flush cycle (as the flush valve collapses toopen, and floats back to the neutral position once buoyancy isrestored).

Ballast Weights

The float region switches from buoyant (floating at the top of the waterin the tank) to non-buoyant (sinking to allow water into the toiletbowl). The neutral buoyancy of the float region may be modified byadding buoyant or non-buoyant weighting material (weights). In oneversion, additional weight (e.g. ceramic plastic, concretes, or metalweights) may be added to the float region. In one version the weightingmaterial is ballast. Weights maybe adjustably added by a user orpermanently affixed to the float region. In one version, weights areadded to the inside of the float region. In one version, weights areadded to the outside of the float region. Buoyant material may also beadded to increase the buoyancy of the float region.

The density of the flush valve (e.g. the density of the material fromwhich the flush valve is fabricated) may determine the weight of theflush valve. Most collapsible flush valves will be fabricated of amaterial having a density near enough to that of water so that when theflush valve is completely submerged, the flush valve will not sink(collapse) unless there is at least one additional force (e.g. springforces, etc) acting on the collapsible member of the flush valve. Thus,it may be desirable to include ballast weight so that the flush valvewill sink or collapse to the proper stopping position in the toilet tankand therefore empty the tank to an appropriate level.

In some versions of the flush valve, the collapsible member is relaxedin the extended position. Ballast weights may be helpful in theseversions, particularly when the flush valve is composed of a materialhaving a density which is sufficiently near (or less than) that ofwater. Thus, ballast weights, counterweights, springs, or somecombination may be assist the flush valve in collapsing to theappropriate level from the relaxed (extended) position.

In one version, weights are made of a water, corrosion and/or chemicallyresistant material. For example, high density plastics, metals,ceramics, concretes, or any combination thereof may be used to make theweights. In on version, ceramics such as porcelain or concrete materialsare used. Weights may be affixed to the float region passively (e.g. bysitting inside of the float region) or actively (e.g. by fastening tothe float region). In one version, the float region includes a fastenerat the bottom surface of the float region to which a weight may beattached.

Guiding Rod

In one version the flush valve includes a rod or shaft 501. FIG. 5Bshows an example of a flush valve having a shaft 501 positioned in thelong axis of the flush valve. The shaft attaches to the center of thebase unit 101 to provide vertical guidance for the float and collapsiblemembers of the flush valve. The shaft may also help prevent excessivetipping by a tipping actuator when a tipping actuator is used to triggeropening of the flush valve by applying a force against one side of thefloat region. The shaft may also engage with the upper region of theflush valve, though an opening 330 in a support 320 at the base of thefloat region.

The shaft shown in FIG. 5B is centrally located, however a guide shaftor rod may be positioned longitudinally anywhere it can help stabilizeand guide the longitudinal (e.g. collapsing) motion of the flush valve.In one version the rod is located off-center in the lumen of the flushvalve. In one version, the rod is located externally to the lumen of theflush valve. In one version, the flush valve includes a pocket forinserting the guide rod.

The shaft may guide the movement of the opening and closing of the flushvalve. For example, the flush valve motion may be limited by the shaft.In one version, the shaft is rigid, and prevents excessive lateralmotion of the flush valve. Thus, the flush valve may be prevented frominterfering with other components in the toilet tank, for example. Somelateral (‘tipping’) motion may be desired, particularly when initiatingopening of the flush valve. Limited lateral motion may be permitted whenthe flush valve includes a shaft, for example, by creating an openingthrough a support 320 in the base of the float region which has a largerdiameter than the outer diameter of the shaft. In FIG. 3C, the opening330 for the shaft is elliptical, allowing tipping, but limitingexcessive lateral motion because of the guide rod which has a circularouter diameter. Furthermore, tipping is permitted in only the directionof the longer diameter of the elliptical opening 330.

A shaft may also limit vertical movement may of the flush valve. In oneversion, the shaft has a vertical stop (e.g. a region of greaterdiameter) preventing the float region from extending past the top of theshaft. Additional stops may be located at other regions on the shaft tolimit the downward movement of the float region of the flush valve. Forexample, the flush valve may be prevented from falling to the bottom ofthe toilet tank in order to limit the amount of fluid passed per flush.

A vertical stop may also prevent the toilet tank from overflowing. Ifthe water level in the tank fills above the upper rim of the flush valvefloat region when the flush valve is kept from extending furthervertically by a vertical stop, the flush valve will activate, flush thetoilet tank and preventing overflow of the tank.

In one version, the guiding shaft is hollow and allows water to passthrough the output port of the toilet tank without opening the flushvalve. In some versions, it may be desirable to pass a small volume ofwater into the toilet bowl without opening the flush valve, for example,when the tank is refilling following a flush cycle. Water may bedirected through the central channel of the closed flush valve by anelbow joint connected to the tank inflow valve. In one version, theguiding shaft is located within the lumen of the flush valve andconnected to the tank inflow valve, allowing some water to pass throughthe flush valve as the tank is refilling. The small amount of waterpassed into the tank after the flush cycle may enhance toilet bowlre-filling. In one version, the shaft is 0.5 inches in diameter, and hasa wall thickness of at least 1/16^(th) of an inch.

Durability

Flush valves described and claimed here operate in the water-filledtoilet tank environment. In addition to water, the toilet tank maycomprise chemical, enzymatic, or other additives (e.g. toilet bowlcleansers, deodorizers, etc.) which may detrimentally effect anycomponents of the toilet tank and toilet, particularly the flush valve.

Further, the flush valve should operate over a reasonable lifetime of atoilet tank. For example, a flush valve may operate for at least a year,at least two years, at least five years, or at least ten years.

A flush valve should operate reliably in the harsh toilet tankenvironment. Thus, a flush valve should resist wear, handle repeateduse, and resist stress cracking, as well as be substantially corrosion,water and/or chemically resistant. Deterioration of the flush valve mayresult in loss of surface integrity (e.g. cracking, tearing, orotherwise undesirably allowing water to leak through the flush valve,etc.), or loss of material strength (e.g. allowing regions of the flushvalve to collapse due to water pressure, etc.), or loss of materialcharacteristics (e.g. loss of flexibility during repeatedopening/closings, etc.).

Resistance to Mechanical Stresses

In one version, the flush valve resists mechanical stress (e.g.cracking, creep and/or deformation) by minimizing the forces acting onthe flush valve in the neutral (closed) position. In one version, thespring forces on the collapsible member are reduced or eliminated whenthe collapsible tube is in the extended position (the position that thecollapsible tube would naturally be in when the flush valve is closed).Thus, the collapsible tube at rest is substantially extended. When thecollapsible tube is collapsed, the spring forces oppose the compressionof the collapsible tube. Since spring forces will only significantly acton the flush valve collapsible tube when it is opened, material fatiguemay be decreased.

In the neutral state the toilet tank is full of water, and the flushvalve is closed; the float region is substantially at the surface of thewater in the tank, and the collapsible member is substantially extendedso that the upper region of the flush valve is held above the watersurface. In practice, the majority of the lifetime of an installed flushvalve is spent in this position. The float region and any weightingmaterial (weights) displace a volume of water whose weight is equal tothe combined weight of the float region and the weights in the neutralposition. When the upper rim of the float region is forced below thesurface of the water in the tank (e.g. by action of the tippingactuator), the float region is flooded, and is now negatively buoyantbecause of the added weight of the water in the float region. Thenegative buoyancy causes the float region to descend, or sink, withinthe toilet tank, to a predetermined stop position. Sinking the floatregion also causes the collapsible member to compress. If thecollapsible tube is configured so that the spring force (e.g. materialforces, etc) are minimized when the flush valve is in the neutralposition, then the spring forces will be oppose the sinking of the floatregion when the collapsible region collapses.

The degree to which the float region is negatively buoyant is dependantupon the weight of the float region and any weighting material (e.g.ballast weights) as well as the density of the float region material,the weight of the flood water volume, and the force exerted upon thefloat region by the collapsible member, which varies with the positionof the collapsible tube (e.g. spring forces). The force of the watermoving from the tank into the central passage of the flush valve mayalso contribute a force component. Water empties from the tank and intothe toilet bowl through the central passage of the negatively buoyantflush valve.

The flushing action of the flush valve is completed when the tank waterlevel has been reduced so that the tank water level is at the sameheight as the rim of the float region (now at its lowest position), andafter the residual flood water volume has sufficiently drained into thethroat of the central passage of the flush valve. The float region thenbecomes positively buoyant as the weight of the residual flood water isreduced. Once buoyancy is restored, the float region of the flush valverises in conjunction with an increasing tank water level.

In one version, the flush valve is designed so that material stressesacting on (and material fatigue of) the flush valve is reduced orminimized. In particular, material stresses acting on the collapsiblemember may be reduced or minimized, for example, by optimizing the sizeand thickness of the threads in the bellows-type collapsible tubes.

In general, the material chosen for all or regions of the flush valve(e.g. the collapsible member) may be selected to effect the mechanicalproperties (e.g. spring modulus) and durability of the flush valve.

Resistance to Chemical Degradation

Chemicals and components added to toilet water may be powerfulcorrosives or degrading agents which may otherwise reduce thedurability, performance and lifetime of the flush valve. Thus, it isimportant that the flush valve, particularly the regions of the flushvalve exposed to toilet tank water when the valve is closed, beresistant water and to some, most, or all of the corrosive or degradingagents. Materials resistant to degrading agents are materials that donot substantially deteriorate in the presence of degrading agents (e.g.halogen-containing toilet disinfectant solutions). Materials that do notsubstantially deteriorate will maintain flush-valve integrity (e.g.prevent water from leaking through the flush valve); this includesmaintaining material strength and material characteristics of the flushvalve (e.g. flexibility and resistance to water pressure).

In one version, at least the outer surface of the flush valve comprisesa material resistant to chlorine (Cl) containing compounds, ions, oragents. Cl-containing ions, compounds or agents include, but are notlimited to, Cl⁻, percholorides, chlorides, chlorates, percholorates,(e.g. hydrochloric acid, hypochlorite bleach,trichloro-s-triazinetrione, etc.).

In one version, at least the outer surface of the flush valve comprisesa material resistant to bromine (Br) containing compounds, ions, oragents. Br-containing ions, compounds or agents include, but are notlimited to, bromine, oxides of bromine, hydrides of bromine, (e.g.sodium tetraborate pentahydrate, etc).

In one version, at least the outer surface of the flush valve comprisesa material resistant to ingredients often present in commerciallyavailable toilet water additives, such as bowl cleaners, deodorants,etc. For example, the material comprising the flush valve may beresistant to ingredients in (or produced by) toilet water additivesincluding isobornyl acetate, sodium carbonate, sodium sulfate,hydroxyethyl cellulose, cocamide MEA, sodium carbonate, FD&C Blue #1,sodium chloride, pine oil, sodium dodecylbenzenesulfonate, sodiumC₁₄-C₁₆ olefin sulfonate, organic chlorine bleach, sodium tetraboratepentahydrate, Acid Blue #9, aluminum sulfinate,trichloro-s-triazinetrione, n-alkyl dimethyl benzyl ammonium chlorides,n-alkyl dimethyl ethylbenzyl ammonium chlorides, ammonium chlorides,isopropyl alcohol, sodium lauryl sulfate, ammonium ions (e.g. atconcentrations of from 0.05 to 2.5 ppm free ammonia), and other halogencontaining (and releasing) sanitizing agents (such as N-halogenatedorganic compounds, e.g., brominated phthalimides, p-toluenesulfonamides, azodicarbonamidines, hydantoins, glycoluracils,cyanurates, amines, melamines, N-chloro-phthalamide,N-bromo-phthalamide, N-dichloro-p-toluene sulphonamide,2,5-N,N′-dichloro-azodicarbonamidine hydrochloride,N,N′-dichloro-dimethyl-hydantoin, N-bromo-N′-chlorodimethyl-hydantoin,N,N′-dibromo-dimethyl-hydantoin, N-bromo-N-chloro-diphenyl-hydantoin,bromocholoro-5,5-dimethylhydantonin,1,3-dichloro-5-ethyl-5-methylhydantonin,1,3-dibromo-5,5-dimethylhydantoin (DBDMH),1,3-dichloro-5,5-dimethylhydantoin (DCDMH),1-bromo-3-chloro-5,5-dimethylhydantoin (BCDMH), dichloroisocyanuric acidand its sodium and potassium salts, trichloroisocyanuric acid (TCICA),hypochlorite ion-releasing agents (e.g., calcium hypochlorite andlithium hypochlorite, N,N,N,N-tetrachlorodimethyl-glycoluracil,N-bromo-N,N-dichloro-dimethylglycoluracil,N,N′-dibromo-dimethyl-glycoluracil, N,N,N,N-tetrachloro-glycoluracil,N,N-dichlorodichloroyl, N-bromo-N-chloro-sodium cyanurate, dibromotriethylene diamine dihydrochloride, bromo-chlorotriethylene diaminedihydrochloride and N,N,N-trichloro-melamine).

Of special interest are materials that have long-term resistance tochemicals used in resident toilet disinfectant compositions, which areoften made into pills, pellets, or the like and placed in the toilettank for extended periods. These compositions usually release chlorine(or other halogens) and related materials over extended lengths of time.For instance, many such compositions include as active disinfectant andcleansing components, halogen-releasing agents such as chloramines;chlorimines; chloramides; chlorimides; halogenated isocyanurates,including heterocyclic N-bromo and N-chloro cyanurates; halogenatedmelamines such as N,N,N-trichloromelamine; N-chlorosuccinimide; alkalimetal or alkaline earth metal hypochlorites, e.g., calcium hypochloriteand lithium hypochlorite; halogenated phthalamides such asN-chloro-phthalamide and N-bromophthalamide; and the halogenatedhydantoins, particularly halogenated 5,5-dialkyl-substituted hydantoins.Examples of particular hydantoins found in residential toiletdisinfectants include 1-bromo-3-chloro-5,5-dimethylhydantoin,1,3-dichloro-5,5-dimethylhydantoin, 1,3-dibromo-5,5-dimethylhydantoin,1-bromo-3-chloro-5,5-diethylhydantoin,1,3-dichloro-5,5-diethylhydantoin, 1,3-dibromo-5,5-diethylhydantoin,1-bromo-3-chloro-5-methyl-5-ethylhydantoin,1,3-dichloro-5-methyl-5-ethylhydantoin,1,3-dibromo-5-methyl-5-ethylhydantoin,1-bromo-3-chloro-5-methyl-5-n-propylhydantoin,1,3-dichloro-5-methyl-5-n-propylhydantoin,1,3-dibromo-5-methyl-5-n-propylhydantoin, and the like.

Toilet cleaning agents may release (typically at a controlled,substantially constant, rate) halogens into the tank water at aconcentration in the range of 0.5 to 5 ppm perhaps with values of pHranging of from about 6.5 to about 10, over its entire life of 2 toabout 4 months of constant contact with water. A single block maydeliver a uniform level of halogen (0.5-3 ppm) for about 1700 to 2100flushes and will be completely dissolved at the end of its useful life.

In one version of the flush valve, the fluid-contacting surfaces of theflush valve comprise a material or materials substantially resistant tothe toilet water chemical additives. Examples of such appropriateresistant materials are described below in the section titled“Materials,” and may include polyolefins.

In one version, at least the outer surface of the flush valve comprisesa material resistant to enzymes. In one version, at least the outersurface of the flush valve comprises a material resistant to amines. Inone version, at least the outer surface of the flush valve comprises amaterial resistant to borax.

Fabrication

The flush valve described herein may be fabricated as a singlecontinuous piece, for example, by injection molding or blow-formmolding. In particular, fabrication of a single continuous piece meansthat all (or most) of the surfaces of the flush valve that contact waterwhen the flush valve is “closed” in a filled toilet tank are a singleintegrated piece (e.g., without seals or connectors). Minimizing thenumber of components of the flush valve reduces the cost, and complexityand likelihood of failure or leakage of the flush valve. In one version,the flush valve base region, collapsible member and float regions areall regions of a single piece such that these three regions do notrequire further connecting or seals. In one version, the base region andthe collapsible member are fabricated as a single piece that does notrequire further connection or seals. In one version, the collapsiblemember and the float region are fabricated as a single piece that doesnot require further connection or seals.

In one version, the flush valve is injection molded. In general,injection-molding involves the steps of: (a) feeding a composition intothe heating chamber of a molding machine and heating the composition toform a molten composition; b) injecting the molten composition into amold cavity; c) maintaining the composition in the mold under highpressure until it cools; and d) removing the molded article.

In one version of the flush valve, flush valve is tapered to facilitateremoval of the flush valve from the mold. In one version, the injectionmold has a central core for shaping the inner surface of the flushvalve. Bellows-type structures, such as the collapsible member of someversions of the flush valve, are difficult to remove from a central coreof an injection mold once formed. However, when the collapsible tube isconfigured as a continuous “screw” shape (as described above), thecollapsible member of the flush valve may be formed between the walls ofan injection mold, and later “unscrewed” to remove the central moldcore.

FIG. 5A shows a flush valve which is formed as a single piece. The flushvalve of FIG. 5A has a number of features which facilitate fabricationby a molding technique such as injection molding. First, the collapsiblemember 103 has one or more threads 501 which extend from the upperportion all the way to the base region 101. Thus, the flush valve may be“unscrewed” from the central region of a mold. Second, the collapsiblemember of the flush valve shown in FIG. 5A is tapered. The innerdiameter of the flush valve generally decreases from the bottom of theflush valve to the top of the flush valve (from the base region to thefloat region). Tapering makes removal from a central region of a moldeasier; particularly when combined with the threaded collapsible tubedesign described above. In threaded and tapered versions of the flushvalve, the central core of a mold can be withdrawn after unscrewing thecollapsible member even a short distance (e.g. a quarter of a rotation).Finally, the flush valve of FIG. 5A is substantially radiallysymmetrical, further facilitating removal of the central region of amold. Radial symmetry allows a central mold to be loosened by rotation,a feature that is particularly helpful when the collapsible region ofthe flush valve is threaded.

Any of the features described above for the version of the flush valveshown in FIG. 5A may be used alone or in combination with other featuresto facilitate fabrication of the flush valve.

The flush valve described herein may be fabricated by any method capableof creating an integrated flush valve. Thus, variations and modificationof the general injection molding technique described above arecontemplated, including but not limited to reactive injection molding,rotational molding, thermoforming, vacuum molding, blow molding,gas-assist or water-assist injection molding, etc.

Once a flush valve is fabricated, it may be treated or furtherprocessed. It is desirable to minimize amount of post-molding processingthat a flush valve undergoes, to simplify the fabrication process and toreduce the cost of fabrication. Example of post-fabrication processingincludes but is not limited to: cutting, shaping, heating, baking,coating, and connecting to additional components.

In one version, the flush valve is treated after fabrication to set theneutral (relaxed) shape of the collapsible member by expanding orcompressing the collapsible member and applying heating to reset theshape. In some versions, the flush valve is fabricated so that thecollapsible member is substantially extended in the neutral position.

In one version of the flush valve, the outer surface of the flush valveis fabricated as a single piece, by injection molding.

Materials

The flush valve or its components may be made of one or more materialscapable of withstanding the environment of the toilet tank whilemaintaining the integrity of the outer (fluid contacting) surface aftermany opening/closing cycles of the flush valve. For instance, usefulmaterials include various polymers (including thermoplastics andthermoset plastics), rubbers, and mixtures thereof. Of particular valueare moldable thermoplastics. Examples of useful polymers include, butare not limited to polyolefins, such as polyethylenes (e.g. Very LowDensity Polyethylene (VLDPE), Ultra Low Density Polyethylene (ULDPE),plastomers, etc., particularly those having a density between about 0.86to about 0.92 g/cc), polypropylenes, chlorinated vinyl resin selectedfrom the group consisting of polyvinyl chloride, postchlorinatedpolyvinyl chloride, polyvinylidine chloride and copolymers thereof, andchlorinated rubbers, polyvinyl chlorides (e.g. soft vinyls such asTygon®), and mixtures thereof, such as thermoplastic elastomers (e.g.thermoplastic vulcinates and other blends of polypropylene and/orpolyethylene with rubbers, etc.).

In one version, the outer surface of the flush valve is made of amaterial which is corrosion and/or degradation resistant. As describedabove, it is beneficial that the flush valve be made of a material thatis resistant to chemicals present or added to toilet water, such aschlorines, bromines, enzymes and amines, etc. (including those describedabove in the section entitled “Resistance to Chemical Stress”). In oneversion, the outer surface of the flush valve is made of a material thatis can be readily fabricated. In one version, the outer surface of theflush valve is made of a material that can be fabricated by injectionmolding.

In one version, the flush valve is comprised of a material which has amodulus of between about 300 and 3000 psi. In one version, the flushvalve is comprised of a material having a high environmental stresscrack resistance (ESCR). In one version, the flush valve is comprised ofa material having a high fatigue life.

In one version, the flush valve is comprised of a material having anoperating temperature range of between about 32 and 120° F. In oneversion, the flush valve is comprised of a material having a low moduluschange over a temperature range of between about 32 and 120° F.

In one version, the flush valve is comprised of a material that isreadily moldable. In one version, the flush valve is comprised of amaterial that is readily blow moldable. In one version, the flush valveis comprised of a material that is readily injection moldable. In oneversion, the flush valve is comprised of a material that is readily blowmoldable and injection moldable. In one version, the flush valve iscomprised of a material that has a melt index above about 3. In oneversion, the flush valve is comprised of a material that has a meltindex of approximately 10.

In one version, the flush valve is comprised of a material that has arelatively high toughness. In one version, the flush valve is comprisedof a material that has a relatively high abrasion resistance. In oneversion, the flush valve is comprised of a material that has arelatively high puncture resistance.

Examples of thermoplastic materials are acetals, acrylics, celluloseacetates, the Nylons, polyolefins (such as polyethylene, polypropylene,polybutylene, t-butylene, their mixtures, alloys, and mixed copolymersand block copolymers), polystyrene, vinyl, and nylon amino,polycarbonate, polystyrene, ABS (acrylonitrile-butadiene-styrene), SAN(styrene-acrylonitrile), and PVC (polyvinylchloride). Thermoplasticelastomers (TPEs) may be particularly desirable. Thermoset materialsinclude amino, epoxy, phenolic, and unsaturated polyesters.Thermoplastic Polyolefin Elastomers (TPOs) are also desirable.Characteristics of plastics materials can be changed by mixing orcombining different types of polymers and by adding non-plasticsmaterials such as particulate fillers and plasticizers.

Examples of rubber materials that may be used include, but are notlimited to halogen-free diene rubbers, hydrogenation products ofhalogen-free diene rubbers, acrylic rubbers, epichlorohydrin rubbers,olefin rubbers, halogen-containing rubbers, silicone rubbers, purerubbers, fluorinated rubbers, and fluorinated blends, etc. Mixtures ofrubbers, and polymers may also be useful.

Examples of polyolefins and polyolefin copolymers that may be usedinclude VLDPEs (for example, FLEXOMER DFDA-1095 NT from DOW ChemicalCompany, ExxonMobil EXACT resin 5371), ULDPE (for example, ATTANE 4404 Gfrom DOW Chemical Company), bimodal polyethylene resin (e.g., DowCONTINUUM), HDPE, LLDPE and polypropylene. Examples of soft vinyls thatmay be used include Tygon®.

The flush valve may also be coated with a material which providesprotection or other advantages. For example, suitable coatings mayimprove resistance to corrosion and swelling, and otherwise enhancedurability. Examples of coatings may include but are not limited tohydrophobic coatings (e.g. wax), polymeric coatings (e.g. Ethylene vinylalcohol, etc.), and rubbery coatings (e.g. Silicones).

The flush valve may be colored or transparent. Although the color of theflush valve does not substantially affect the function, the flush valvemay be made to have an aesthetically pleasing color, for example, bydying, painting, coating, etc.

Installation

A flush valve as described herein may be installed into the tank of atoilet by attaching the base region of the flush valve to the tankoutlet port. In one version, the flush valve is attached to the outletport by inserting the base region of the flush valve through the tankoutlet port, and attaching applying pressure to seal the base region ofthe flush valve to the sides of the toilet outlet port. In one version,the base of the outlet port is threaded to attach to a nut. In versionsof the flush valve in which the base of the flush valve is made of anelastomeric material, the flush valve may be sealed in the outlet portby clamping the base region of the flush valve against the tank, e.g.the sides of the outlet port. In one version, the flush valve is clampedto the outlet port by tightening a nut which compresses the base regionof the flush valve against the walls of the outlet port. In one version,the inside of the base region of the flush valve threaded, and the baseregion of the flush valve is inserted into the tank outlet port and athreaded cylinder can be screwed into the base region to apply pressuresufficient to seal the base region into the tank outlet port. Thethreaded cylinder may be tapered so that the base region is slightlyexpanded as the cylinder is tightened, enhancing the seal.

The tank outlet port should be in fluid communication with the toiletbowl, so that fluid passing through the tank outlet port will enter thetoilet bowl.

Operation

FIG. 6 illustrates an example of a flush valve installed in a toilettank. In FIG. 6, the tank portion of the toilet is show partly cut away,revealing the water 601, flush valve 10, tipping actuator 605, andrefilling inflow valve 607. The flush valve 10 is attached to the tankoutlet port 611 at the base region of the flush valve, preventing waterfrom entering the toilet bowl 620. The float region of the flush valveis buoyantly held above the surface of the water. The tipping actuator605 in FIG. 6 is a rigid member attached to a handle 615. The end of thetipping actuator is on or above the edge of the top of the float regionof the flush valve. Moving the handle 615 moves the tipping actuator,and thus, pushes down on the edge of one side of the flush valve,opening the flush valve.

The tipping actuator may be configured so that moving the handle on theoutside of the toilet tank 615 downwards (as in most standard US toilettanks) opens the flush valve. The tipping actuator may also include aspring, buoyant material, counterweight, or some combination thereof toreturn the actuator to the rest position immediately after flushing thetoilet.

Although the tipping actuator is shown as a rigid member that may bepivoted by moving the handle, the tipping actuator may be any devicecapable of submerging at least one edge of the float region of the flushvalve. The tipping actuator may submerge the entire float region. Thus,the tipping actuator may be a chain, lever arm, or plunger. It ispreferable that the tipping actuator be controlled by the user from theside of the tank, for example by a handle means, as shown in FIG. 6. Aswill be apparent to those in the art, the handle means may be locatedanywhere on the toilet tank, including the top and sides. In addition tothe components shown in FIG. 6, a toilet using a flush valve asdescribed herein may include additional components, or other versions ofthe components shown in the FIG. 6. For example, the refilling inflowvalve 607 may include a different float valve for detecting the filllevel of the tank. An elbow joint may be attached to the inflow valve toapply water directly down the flush valve when the tank is beingrefilled.

FIG. 7A to 7C shows the flush valve being opened. In FIG. 7A, the flushvalve is closed, but poised for activation by the tipping actuator 605.The collapsible flush valve is in the neutral position, fully extended.The tank is full of water 703, which is prevented from exiting theoutput port of the tank by the walls of the flush valve 10. In FIG. 7Bthe tipping actuator has been moved from its neutral resting positionabove (or on) the upper edge of the float region of the flush valve sothat it contacts an edge of the float region of the flush valve. Thetipping actuator applies sufficient force to the float region of theflush valve to overcome the buoyant forces keeping the float regionabove the water, and submerging at least part of the float region. Oncethe float region takes on water (as shown), the weight of the water alsocounteracts the buoyant forces of the float region, and top (floatregion) of the flush valve drops down towards the bottom of the tank asshown in FIG. 6C. The collapsible member of the flush valve collapses topermit the flush valve to sink. Water from the tank enters the flushvalve, and drains out to the toilet bowl. Thus, the collapsible memberof the flush valve collapses from the neutral extended position into thecollapsed state.

The flush valve is turned off once the water in the tank has drained toa level approximately equal to the top of the float region, and thefloat region can no longer sink. Buoyancy of the float region is fullyrestored once the water in the float region (which is weighing down thefloat region) drains into the flush valve. As the tank is refilledthrough the tank inlet valve, the float region rises with the surface ofthe water in the tank. After the tank is completely refilled, the floatregion of the flush valve is once again at the top of the water level,and the flush valve is fully closed, and ready to be activated by thetipping actuator.

Although illustrative variations of the flush valve have been describedabove, it will be evident to a skilled artisan that various changes andmodifications may be made without departing from the true scope andspirit of the flush valve described above and herein claimed. Thevarious examples are, therefore, to be considered in all respects asillustrative and not restrictive.

1. A flush valve for controllably delivering a selected amount of waterto a toilet bowl from a toilet tank, the toilet tank having a watersurface and a tank outlet, comprising: a collapsible member configuredto extend from the water surface to the tank outlet in a first extendedposition and to maintain the water in the toilet tank, and further torelease water from the toilet tank through the tank outlet in a secondlongitudinally collapsed position, wherein the collapsible membercomprises one or more materials that do not substantially deteriorate inthe presence of halogen-containing toilet disinfectant solutions; andwherein the flush valve has no valve seat.
 2. The flush valve of claim1, wherein the flush valve further comprises at least one ballastweight.
 3. The flush valve of claim 1, wherein the collapsible member isfabricated as a single piece by molding.
 4. The flush valve of claim 3,wherein the collapsible member is fabricated as a single piece byinjection molding.
 5. The flush valve of claim 1, wherein thecollapsible member is further configured to be relaxed in the extendedposition.
 6. The flush valve of claim 1, further comprising a tippingactuator for collapsing the collapsible member of the flush valve. 7.The flush valve of claim 1 further comprising a base region and a floatregion that are fabricated with the collapsible member as a continuoussingle piece; and further wherein sinking the float region allows thecollapsible member to collapse and allows water to flow through thecollapsible member and out of the tank outlet.
 8. The flush valve ofclaim 7, wherein the base region, float region, and collapsible memberare fabricated as a single piece by molding.
 9. The flush valve of claim1, wherein the collapsible member is configured as a collapsiblebellows.
 10. The flush valve of claim 9, wherein the collapsible bellowshas a continuous spiral thread.
 11. The flush valve of claim 9, whereinthe collapsible bellows is tapered.
 12. The flush valve of claim 1,wherein the flush valve is fabricated from a polyolefin.
 13. The flushvalve of claim 12, wherein the flush valve is fabricated from a Very LowDensity Polyethylene.
 14. The flush valve of claim 12, wherein the flushvalve is fabricated from an Ultra Low Density Polyethylene.
 15. Theflush valve of claim 1, wherein the flush valve is fabricated from softvinyl.
 16. The flush valve of claim 1, further comprising a longitudinalshaft coupled to the collapsible member wherein the shaft is configuredto substantially guide the flush valve when the collapsible membercollapses.
 17. A flush valve for controllably delivering a selectedamount of water to a toilet bowl from a toilet tank, the toilet tankhaving a water surface and a tank outlet, comprising: a collapsiblemember configured to extend from the water surface to the tank outlet ina first extended position and to maintain the water in the toilet tank,and further to release water from the toilet tank through the tankoutlet in a second longitudinally collapsed position, and furtherconfigured to be relaxed in the extended position; and wherein the flushvalve has no valve seat.
 18. The flush valve of claim 17 wherein theflush valve further comprises at least one ballast weight.
 19. The flushvalve of claim 17 wherein the collapsible member is fabricated as asingle piece by molding.
 20. The flush valve of claim 19, wherein thecollapsible member is fabricated as a single piece by injection molding.21. The flush valve of claim 17, further comprising a tipping actuatorfor collapsing the collapsible member of the flush valve.
 22. The flushvalve of claim 17 further comprising a base region and a float regionthat are fabricated with the collapsible member as a continuous singlepiece; and further wherein sinking the float region allows thecollapsible member to collapse and allows water to flow through thecollapsible member and out of the tank outlet.
 23. The flush valve ofclaim 22, wherein the base region, float region, and collapsible memberare fabricated as a single piece by molding.
 24. The flush valve ofclaim 17, wherein the collapsible member is configured as a collapsiblebellows.
 25. The flush valve of claim 24, wherein the collapsiblebellows has a continuous spiral thread.
 26. The flush valve of claim 24,wherein the collapsible bellows is tapered.
 27. The flush valve of claim17, further comprising a longitudinal shaft coupled to the collapsiblemember wherein the shaft is configured to substantially guide the flushvalve when the collapsible member collapses.
 28. A flush valve fordelivering water to a toilet bowl from a toilet tank comprising: a baseregion configured to connect to the outlet port of a toilet tank; afloatable and sinkable float region having an opening that is held abovethe surface of the water when the float region is floating, and whereinthe float region is linked to the base region through a collapsiblemember extending from the base region to the float region; wherein thebase region, float region and collapsible member are fabricated as asingle piece, and further wherein sinking the float region allows waterto flow through the opening of the float region and out of the outletport of the toilet tank.
 29. The flush valve of claim 28 furthercomprising at least one ballast weight.
 30. The flush valve of claim 28,wherein the base region, float region and collapsible member arefabricated as a single piece by molding.
 31. The flush valve of claim30, wherein the base region, float region and collapsible member arefabricated as a single piece by injection molding.
 32. The flush valveof claim 28, further comprising a tipping actuator for collapsing thecollapsible member of the flush valve.
 33. The flush valve of claim 28,wherein the collapsible member is configured as a collapsible bellows.34. The flush valve of claim 33, wherein the collapsible bellows has acontinuous spiral thread.
 35. The flush valve of claim 33, wherein thecollapsible bellows is tapered.
 36. The flush valve of claim 28, furthercomprising a longitudinal shaft coupled to the collapsible memberwherein the shaft is configured to substantially guide the flush valvewhen the collapsible member collapses.
 37. A flush valve forcontrollably delivering a selected amount of water to a toilet bowl froma toilet tank, the toilet tank having a water surface and a tank outlet,comprising: a collapsible member configured to extend from the watersurface to the tank outlet in a first extended position and to maintainthe water in the toilet tank, and further to release water from thetoilet tank through the tank outlet in a second longitudinally collapsedposition; and a ballast weight sufficient to collapse the collapsiblemember, wherein the flush valve has no valve seat.
 38. The flush valveof claim 37 wherein the collapsible member is fabricated as a singlepiece by molding.
 39. The flush valve of claim 38, wherein thecollapsible member is fabricated as a single piece by injection molding.40. The flush valve of claim 37, further comprising a tipping actuatorfor collapsing the collapsible member of the flush valve.
 41. The flushvalve of claim 37, wherein the collapsible member is configured as acollapsible bellows.
 42. The flush valve of claim 41, wherein thecollapsible bellows has a continuous spiral thread.
 43. The flush valveof claim 41, wherein the collapsible bellows is tapered.
 44. The flushvalve of claim 37, further comprising a longitudinal shaft coupled tothe collapsible member wherein the shaft is configured to substantiallyguide the flush valve when the collapsible member collapses.
 45. A flushvalve for controllably delivering a selected amount of water to a toiletbowl from a toilet tank, the toilet tank having a water surface and atank outlet, comprising: a molding-formed collapsible member configuredto extend from the water surface to the tank outlet in a first extendedposition and to maintain the water in the toilet tank, and further torelease water from the toilet tank through the tank outlet in a secondlongitudinally collapsed position, and further configured to be spirallythreaded, wherein the flush valve has no valve seat.
 46. The flush valveof claim 45 wherein the collapsible member is fabricated as a singlepiece by molding.
 47. The flush valve of claim 46, wherein thecollapsible member is fabricated as a single piece by injection molding.48. The flush valve of claim 45, further comprising a tipping actuatorfor collapsing the collapsible member of the flush valve.
 49. The flushvalve of claim 45, wherein the collapsible member is tapered.
 50. Theflush valve of claim 45, further comprising a longitudinal shaft coupledto the collapsible member wherein the shaft is configured tosubstantially guide the flush valve when the collapsible membercollapses.
 51. A flush valve for controllably delivering a selectedamount of water to a toilet bowl from a toilet tank, the toilet tankhaving a water surface and a tank outlet, comprising: a collapsiblemember configured to extend from the water surface to the tank outlet ina first extended position and to maintain the water in the toilet tank,and further to release water from the toilet tank through the tankoutlet in a second longitudinally collapsed position, and furtherconfigured to be relaxed in the extended position, wherein thecollapsible member comprises one or more materials that do notsubstantially deteriorate in the presence of halogen-containing toiletdisinfectant solutions; and wherein the flush valve has no valve seat.52. A flush valve for controllably delivering a selected amount of waterto a toilet bowl from a toilet tank, the toilet tank having a watersurface and a tank outlet, comprising: a collapsible member configuredto extend from the water surface to the tank outlet in a first extendedposition and to maintain the water in the toilet tank, and furtherconfigured to release water from the toilet tank through the tank outletin a second longitudinally collapsed position, wherein the collapsiblemember comprises one or more materials that do not substantiallydeteriorate in the presence of halogen-containing toilet disinfectantsolutions, and wherein the collapsible member is fabricated as a singlecontinuous piece; and wherein the flexible valve has no valve seat. 53.A flush valve for controllably delivering a selected amount of water toa toilet bowl from a toilet tank, the toilet tank having a water surfaceand a tank outlet, comprising: a collapsible member configured to extendfrom the water surface to the tank outlet in a first extended positionand to maintain the water in the toilet tank, and further configured torelease water from the toilet tank through the tank outlet in a secondlongitudinally collapsed position, wherein the collapsible membercomprises one or more materials that do not substantially deteriorate inthe presence of halogen-containing toilet disinfectant solutions, andwherein the collapsible member is fabricated as a single continuouspiece, and further wherein the collapsible member is configured to besubstantially relaxed in the extended position.
 54. A flush valve fordelivering water to a toilet bowl from a toilet tank comprising: a baseregion configured to connect to the outlet port of a toilet tank; afloatable and sinkable float region having an opening that is held abovethe surface of the water when the float region is floating, and whereinthe float region is linked to the base region through a collapsiblemember extending from the base region to the float region; at least oneballast weight; wherein the collapsible member is relaxed in theextended position, and further wherein the base region, float region andcollapsible member are fabricated as a single piece, and further whereinsinking the float region allows water to flow through the opening of thefloat region and out of the outlet port of the toilet tank.
 55. A flushvalve for controllably delivering a selected amount of water to a toiletbowl from a toilet tank, the toilet tank having a water surface and atank outlet, comprising: a collapsible member configured to extend fromthe water surface to the tank outlet in a first extended position and tomaintain the water in the toilet tank, further configured to releasewater from the toilet tank through the tank outlet in a secondlongitudinally collapsed position, and further configured to be relaxedin the extended position, and at least one ballast weight sufficient tocollapse the collapsible member; wherein the collapsible membercomprises one or more materials that do not substantially deteriorate inthe presence of halogen-containing toilet disinfectant solutions, andwherein a region of the collapsible member is configured as acollapsible bellows having at least one continuous thread, and whereinthe collapsible member is fabricated as a single continuous piece byinjection molding.
 56. A method of installing a flush valve in a toilettank having an outlet port in fluid connection with a toilet bowlcomprising: providing a flush valve comprising: a base region configuredto connect to the outlet port of a toilet tank; a variably buoyant floatregion configured to switch between a high buoyant state and a lowbuoyant state, and having an opening that is held above the surface ofthe water when the float region is highly buoyant, and further whereinthe float region is linked to the base region through a collapsiblemember extending from the base region to the float region; wherein thefloat region and the collapsible member are fabricated as a singlepiece; installing the flush valve on the outlet port of a toilet tank.57. The method of claim 56 wherein the flush vale is installed bytightening a nut.